Scholarship and Biography
We study complex organic materials by advanced solid-state NMR and chemical energy by quantitative thermodynamic analysis. Most importantly, we have developed the oxygen theory of combustion and respiration energetics, which shows quantitatively that O2 is a high-energy molecule. This means that our bodies get most of their energy not from the food we eat but from the oxygen we breathe.
We characterize the composition and nanoscale structure of complex organic materials, in particular polymers, carbon materials, metal–organic frameworks, nanocomposites, and natural organic matter, using quantitative or selective one- and two-dimensional nuclear magnetic resonance (NMR) experiments, often developed by us. We have also introduced methods for quantitative analysis of scattering data of nanostructured materials. This dual approach has enabled us to “solve” important aspects of the structure of the Nafion fuel-cell membrane, of the nanocomposite in bone, and of chain trajectories in semicrystalline polymers. Based on such structural insights, we strive to understand materials properties and sometimes propose improved synthesis or processing conditions.
In the area of chemical energy, we have worked out quantitatively how batteries store energy in weak bonds of certain metals and release it when more strongly bonded metals form, and that fire is hot due to chemical energy stored in oxygen molecules with their relatively weak double bond, regardless of the organic fuel. This has revealed fundamental misconceptions in traditional descriptions of bioenergetics, which fail to explain the energetics of respiration and fermentation of carbohydrates and fats, of the two photosystems in plants, and of bioluminescence. High-energy O2 immediately provides the needed explanations.
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Journal article
Published 12/2024
Solid state nuclear magnetic resonance, 134, 101973
The molecular structure of hydrochars produced from 13C-enriched glucose under various conditions has been elucidated based on advanced one- and two-dimensional (2D) 1H-13C and 13C-13C solid-state nuclear magnetic resonance (NMR) with spectral editing. Regardless of synthesis conditions, hydrochars consist mostly of oxygen-substituted arene rings (including diphenols) and furans connected by alkyl linkers rich in ketones. Cross-linking nonprotonated and methyne (C-H) alkyl carbons have been identified through spectrally edited 2D NMR. Alkenes and ‘quaternary’ C-O are observed only at low synthesis temperature, while some clusters of fused arene rings are generated at high temperature. Hydrochar composition is nearly independent of reaction time in the range from 1 to 5 h. Equilibration of 13C magnetization within 1 s shows that the materials are homogeneous on the 5-nm scale, refuting core–shell models of hydrochar microspheres. While furan C-O carbons bonded to alkyl groups or ketones show distinctive cross peaks in 2D NMR, phenolic C-OH is observed unambiguously by hydroxyl-proton selection. While methylene-linked furan rings are fairly common, the signal previously assigned to furan Cα-Cα linkages is shown to arise from abundant, stable catecholic ortho-diphenols, whose HO-C=C-OH structure is proved by 2D 13C-13C NMR after hydroxyl-proton selection. Quantitative 13C NMR spectra of low- and high-temperature hydrochars have been matched by chemical-shift simulations for representative structural models. Mixed phenol and furan rings connected by ketones and alkyl linkers provide good fits of the experimental spectra, while literature models dominated by large clusters of fused rings and with few phenols or alkyl-linked ketones do not. [Display omitted] •9 hydrochars made from 13C-enriched glucose were studied by advanced solid-state NMR.•Effects of synthesis temperature, duration, and pH on structure were investigated.•Hydrochars consist mostly of diphenols, furans, and alkyl linkers rich in ketones.•Models with these components match the NMR spectra, while literature models do not.•13C spin exchange shows 5-nm homogeneity, refuting core–shell models of hydrochar.